1. Field Of The Invention
The invention relates to a novel process for the preparation of trialkyl ester derivatives of the general formula: ##STR3## wherein X is chlorine, bromine, iodine, tosyloxy- or mesyloxy- and R is a C.sub.1 -C.sub.6 -alkyl group.
2. Background Art
Trialkyl ester derivatives of the formula I, for example, bromo triethyl esters, are valuable intermediates in the preparation of antiviral nucleotide derivatives (European Published Patent Application 0369583).
The preparation of bromo triethyl ester starting from triethyl methanetricarboxylate and dibromoethane in the presence of sodium ethanolate is known [H. Rapoport et al., J. Org. Chem., Vol. 44, No. 20, (1979), 3492-3496]. However, this prior process has, on the one hand, the disadvantage that the corresponding product is heavily contaminated with by-products and the fact, on the other hand, that it is uneconomic owing to relatively long reaction times involved.